Electric switch



Oct. 1, N. Q BEESE ELECTRIC SWITCH Filed July 30, 1952 ATTORNQ/ lvENToR Af. C. BEE E' lilffrf y 4 4 Patented Oct. 1, 1935 UNITED STATES ELECTRIC SWITCH Norman C. Beese, Verona, N. J., assigner to Westmghouse Lamp Company, a. corporation of Pennsylvania Application July 30, 1932, Serial No. 626,473

sciaims. (c1. 20o- 144) This invention is directed to an electric switch and more particularly to a switch of the vacuum type for accomplishing the make and break of an electric circuit. In its more specic aspect the invention relates to a simplified rugged switch adapted to close a high potential circuit of which it may be a part.

A n object of my invention is to provide la relatively inexpensive and lsimple vacuum switch of relatively light weight.

AnotherY object of my invention is to provide a vacuum switch of simple and economical design .adapted to have a relatively long operating life even when employed in an X-ray circuit.

l5 Another object of my invention is to provide a rugged vacuum switch which is of relatively light weight and small size so that when it is combined with other elements of an X-ray apparatus it will not necessitate heavy and cumbersome frames and supporting standards.

Other objects of my invention will become readily apparent from the following specification and appended drawing wherein; Figure 1 represents a longitudinal cross-sectional view with some of the parts in elevation of a vacuum switch embodying my invention;`

Figure 2 is a cross-sectional perspective view on an enlarged scale of aV spring member embodied in the construction of my invention;

Figure 3 illustrates a modification on an enlarged scale of the contact elements shown in Figure l; and

Figure 4 illustrates a further modication on an enlarged scale of the contact elements shown in Figure 1.

As illustrated in Figure 1, one aspect of my invention comprises a di-electric highly evacuated envelope I0 consisting of a bulbous mid-portion II and diametrically opposed tubular arms I2 and I3. Extending into said tubular arm I3 is a reentrant tube I4 of appreciably smaller outside diameter than the corresponding internal dimension of said tubular arm I3 and having its outer wall spaced from the inner wall thereof.

The upper or free end 'of said reentrant tube I4 is substantially an annular plane at approximately right angles to the longitudinal axis of said tube. Intermediate said free end and the end of said reentrant tube I4, homogeneously united with the tubular arm I3, is a vitreous disc I5 having sealed thereto a leading-in conductor I6 extending on either side of the faces thereof The disc I5 is fusedly ring sealed to the inner wall of the reentrant tube I4.

Housing that end of the envelope adjacent said disc I5 is a metallic cap I'I to which is connected a conductor I8 extending from and electrically secured to the leading-in conductor I6. Spaced around and slidably mounted on the upper or free end of said reentrant tube I4 is a tubular 5 generally stationary contact I9 composed of molybdenum or the like, and whose internal diameter is approximately the same dimension as the corresponding external dimension of said reentrant tube. 10

The contact I9 is of substantial length so that an appreciable portion thereof may surround a corresponding appreciable portion of the upper end of said reentrant tube I4 in order that the stability of the contact I9 may be always main- 15 tained.

As illustrated, the contact I9 consists essentially of a tubular section 20 having a smooth cratered cap 2| secured thereto with the cylindrical portion of said cap surrounding the outer 20 periphery of one end of said cylindrical section 20. A metallic ring 22 is mounted within the inner periphery of said tubular section at the intermediate portion thereof or any desired point defining the limit of insertion of said reentrant 25 tube I4, in said contact I 9.

'I'he ring 22 is secured to said tubular section I9 by any suitable mechanical means, as for example, screws 23. Between the upper free end of said reentrant tube I4 and said ring 22 and 30 resting on the upper free end of said reentrant tube is an annular thin metallic section 24 having a plurality of thin struck up spring members 25 adapted to bear against the ring 22 to serve the purposes hereinafter more fully outlined. 35 Electrical contact is made between the leadingin conductor I6 and the contact I9 by a flexible conducting element 26 secured to the ring 22 and connected to the leading-in conductor IB. y

On the outside of said reentrant tube I4 is 40 a small vitreous protuberance 21 adapted .to cooperate with a slot 28 in the contact I9 in order to prevent too great longitudinal movement between the contact I9 and the reentrant tube I4 in the direction of the free end of said tube I4. 45 The contact I9 is further longitudinally and laterally slotted as at 29 and 30 so that the lower portion of said contact may be flexible whereby said contact may be mounted on said reentrant 'tube to be snugly and slidably in contact there- 50 with.

'Ihe tubular arm I2 is closed at one end and has sealed therein a leading-in conductor 3| forming an air-tight seal therewith and extendi ing both within and without the envelope. Sur- 55 rounding said seal and a portion of said envelope at one end is a cap 32 electrically connected to that portion of the conductor 3| extending exteriorly of the envelope. At about the midportion of said tubular arm I2 is a reentrant tube 33 having a flanged portion 34 fusedly ring sealed to the inner wall of said arm and the free end of said reentrant tube M is in a direction towards the bulbous portion of the envelope.

Mounted on said reentrant tube 33 is a cylindrical bearing consisting of nickel, Monel metal or other metallic shell I6 having a slot l1 extending longitudinally from one edge thereof to about the midlength thereof', and a lateral slot 38 opening in said longitudinal slot with said lateral slot extending around about one half the circumference of said tubular section. The outer extremity of said slot is preferably widened and is in the form of an L slot in order to accommodate a protuberance 29 of glass or the like, which serves to retain said tubular section in position.

Within said tubular section 22 are mounted a plurality of annular rings 4|) and 4I whose external diameters are approximately equal to the corresponding internal dimension of said tubular section 3E. Said ring 4l is located at about the outer limit or free end of said shell and said ring 4I is located at about the intermediate length of said shell.

'I'his section 36 acts in the capacity of a bearing means on which a relatively movable contact 42 is mounted and adapted to slide and be guided during its sliding movement. The contact 42 consists essentially of a tubular section 43 having a smooth convex cap 44 secured thereto with the outer limit of said tubular shell being surrounded by the cylindrical portion of said cap. Spaced along the length of said tubularsection and mounted therewithin by means of screws are a plurality of metallic spiders or plates 4l and 46. A bearing shaft 41 extends through the opening of said ring 48 and is threadedly secured to the ring whereby movement of said shaft causes movements of said contact.

The shaft 41, whose diameter is slightly less than that of the openings in the rings 4I and 4|, extends through the shell and the reentrant tube 33, with said shaft bearing against and guided by the rings 4|I and 4| during the movement thereof. Loosely mounted on said shaft 41 and located between the bearing plates 4I and 44 is a spring member 4l of the same general type as the member 24.

A soft iron core 4l whose external diameter is less than the corresponding Internal dimension of the reentrant tube 32, is secured to the upper end of said shaft 41. A loosely coiled flexible conductor 5l is connected to the leading-in conductor 2| and the soft iron core 4l so that the potential of the contact 42 shall be approximately the same as that of the cap I2. In order that the contact 42 may be moved relative to the contact I9, a magnetic winding il is. provided exteriorly of the envelope and surrounding the arm I2. i

In normal or general operation the vacuum switch as hereinbefore described is mounted in a substantially vertical position with the contact 42 uppermost. In this position with the mag-` netic winding deenergized, the contact 42 is in its lowermost position with the convex portion 44 thereof contiguous with the crater portion 2| of the contact Il. Upon energization of the magnetic windings the shaft 41 carrying the soft iron core 49 and the contact 42 slides upwardly and away from the contact I9. In the course of the sliding movement the bearings 40 and 4| and the shell 36 serve to guide the contact 42. When the contact 43 is travelling towards the limit of 5 its upward movement, the spring member 4B by virtue of its resiliency acts as a shock-absorbing means to protect the reentrant tube 33 from sudden harsh impacts.

The contact 42 movable with respect to the contact I9 may be maintained in its uppermost position by maintaining the magnetic winding 5I in an energized condition. In order to close the` switch, all an operator need do, is to deenergize the magnetic winding 5| by opening a switch 52 located in an energy supply line 53.

When this is done, the contact 42 together with its shaft 41 and the soft iron core 49 will move downwardly towards the contact I9 because of the force of these elements due to gravity. Motion of these members is substantially arrested when the contact 42 is contiguous with the contact I8, with the convex portion of the contact 42 and the crater of the contact I 8 defining a substantial surface area of contiguity. The resilient spring members 25 serve as shock-absorbers to protect the reentrant tube I4 from sudden harsh impacts when contact is made.

These two operations. of breaking and making a circuit may be repeated by merely energizing and deenergizing the winding.

Instead of employing the contacts I! and 42 as heretofore described it is within the purview of this invention to employ the novel contacts illustrated in Figures 3 and 4. Figures 3 and 4 illustrate the stationary contacts having fiat topped portions 6I instead of the crater 2| secured to the cylinder portion 20. The relatively movable contacts are characterized by novel portions 82 and 63, instead of the convex portion 44 illustrated in Figure 1.

The portion 62 as shown in Figure 3 consists primarily of a cup similar to the flat-topped cup 6| on the stationary electrode. Secured to and depending therefrom is a screw 83 having a plurality of threads. Instead of employing a screw in combination with the cup 64, I may employ the structures illustrated in Figure 4, which shows a block 65 of appreciable cross-section secured to said cup 'and extending therefrom. Se- 50 cured to said block and supported thereby are a plurality of relatively sharp pointed wires 66 whose edges extend up to about, but not beyond, the outer or free vlimit of said block.

With the contact constructions heretofore described and illustrated in Figures 3 and 4, it is possible to initiate a small discharge current due to cold emission, before actual contiguity is established between the contacts thereof. A switch of this character finds utility in a number of different fields and for the purposes of illustration in that field where it is desirable to start the iiow of current before the contacts are contiguous.

Although my invention has been described e5 with some particularity, the scope of my invention is to be limited only by the prior art.

What is claimed is:

1. A'switch comprising an enclosing envelope, a plurality of contacts therein, one of said con- 70 tacts being movable to make and break a circuit, a reentrant tube in said envelope supporting said make and break contact, the other of said contacts being practically stationary, a second reentrant tube in said envelope. said second con- 15 tact including a sleeve slidably mounted for limited movement on said second reentrant tube, resilient means cooperating with the upper f ree end of said second reentrant tube and said contact to allow sliding movement of said sleeve and to so relieve the second reentrant tube from the force of impact upon circuit making.

2. A switch comprising an enclosingl vitreous envelope, a plurality of contacts'thereinfone of said contacts being movable to make and break a circuit, said other contact being practically stationary, a vitreous reentrant tube supported by said envelope, said reentrant tube having a free end, said last mentioned'contact having a sleeve portion surrounding said reentrant tube and mounted thereon, a bearing means in said sleeve, a spring member located between the upper end of said reentrant tube and said bearing means for relieving said reentrant tube from the force of sudden impact on circuit making.

3. A switchcomprising an enclosing vitreous envelope, a plurality ,of contacts therein, one of said contacts being movable to make and break a circuit, said other contact being practically stationary, a vitreous reentrant tube supported by said envelope, said reentrant tube having a free end, said lastl mentioned contact having a sleeve portion surrounding said reentrant tube and mounted thereon, a ring secured to said sleeve and being located within said sleeve intermediate its ends, a spring member having.

struck-up portions bearing against said ring and adapted to be iiexed upon circuit making to relieve said reentrant tube from the force of sudden impact upon circuit making.

4. A switch comprising an evacuated dielectric envelope, a plurality of butt contact members therewithin, one of said contact members being 5 practically stationary and said other contact being movable relative to said other contact member, said contact members being adapted to abuttingly contact each other on circuit making, one of said contacts having a plurality of sharp edges rearwardly of the abutting face thereof for cold electron emission during the period of movement of said contacts relative to each other.

5. A switch comprising a dielectric envelope having a plurality of reentrant tubes and'a plurality of lead-in conductors extending therewithin, a sleeve carried by one of said reentrant tubes, a sleeve mounted on said first sleeve and carrying a contact, a shaft carrying said second mentioned sleeve, a fbearing means carried by said iirst mentioned sleeve, said shaft being adapted to slide in said bearing, a resilient means associated with said sleeves to prevent breakage of saidrst mentioned tube when said contact has attained a predetermined position, one of said lead-in conductors being electrically connected to said contact, a contact carried by said other reentrant tube and resilient means associated withsaid second mentioned contact and tube for preventing sudden stresses on said second mentioned tube during the make operation of the switch.

NORMAN C. BEESE. 

